Examples of device structures utilizing layers of rare earth oxides to perform the tasks of strain engineering in transitioning between semiconductor layers of different composition and/or lattice orientation and size are given. A structure comprising a plurality of semiconductor layers separated by transition layer(s) comprising two or more rare earth compounds operable as a sink for structural defects is disclosed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A structure within a solid state device comprising at least two photovoltaic cells in tandem; the structure comprising; a first solar cell of first composition comprising first and second surfaces; a second region of second composition comprising first and second surfaces; and a second solar cell of third composition comprising first and second surfaces separated from the first region by the second region; the first solar cell and second solar cell being arranged in tandem; wherein the second region consists substantially of first and second rare-earth oxide compounds such that the lattice spacing of the first rare-earth oxide compound is different from the lattice spacing of the second rare-earth oxide compound and wherein the first and second solar cells consist substantially of elements only from Group IV and the third composition is different from the first composition and the first surface of the second region is in contact with substantially all of the second surface of the first solar region and the second surface of the second region is in contact with substantially all of the first surface of the second solar cell and wherein the composition of the second region consists substantially of [RE1] v [RE2] w [RE3] x [J1] y [J2] z wherein [RE] is chosen from a rare earth; [J1] is oxygen and [J2] is chosen from a group consisting of Oxygen (O), Nitrogen (N), and Phosphorus (P), and 0≦v, z≦5, and 0≦w, x, y≦5.
2. A solid state device of claim 1 wherein said second region comprises, a first portion of fourth composition adjacent said first solar cell; a second portion of fifth composition; and a third portion of sixth composition separated from the first portion by the second portion and adjacent said second solar cell wherein the fifth composition is different from the fourth and sixth compositions.
3. A solid state device of claim 2 wherein said second portion comprises a first surface adjacent said first portion and a second surface adjacent said third portion and said fifth composition varies from the first surface to the second surface.
4. A solid state device of claim 2 wherein said second portion comprises a first surface adjacent said first portion and a second surface adjacent said third portion and comprises a superlattice with a structure comprising two layers of different composition which repeat at least once.
5. A solid state device of claim 2 wherein said first portion is in a first state of stress and said third portion is in a second state of stress different than the first state of stress.
6. A solid state device comprising at least two solar cells in tandem; the device comprising; first and second semiconductor layers operable as solar cells in tandem separated by a rare earth layer wherein the first semiconductor layer consists of composition X (1-m) Y m ; the second semiconductor layer consists of composition X (1-n) Y n and the rare earth layer is of a composition consisting substantially of [RE1] v [RE2] w [RE3] x [J1] y [J2] z wherein [RE] is chosen from a rare earth; [J1] is oxygen and [J2] is chosen from a group consisting of oxygen (O), nitrogen (N), and phosphorus (P), and X and Y are chosen from Group IV elements such that 0≦n, m≦1, 0≦v, z≦5, and 0≦w, x, y≦5; and wherein n is different from m.
7. The device of claim 6 wherein said rare earth layer comprises a first and second rare earth layer such that the composition of the first layer is different from the composition of the second layer and the lattice spacing of the first layer is different from the lattice spacing of the second layer.
8. A solid state device comprising at least two solar cells in tandem; the device comprising; first semiconductor layer operable as a solar cell; second semiconductor layer operable as a solar cell; the first semiconductor layer and second semiconductor layer being arranged in tandem; and a rare earth layer comprising regions of different composition separating the first semiconductor layer from the second semiconductor layer; wherein the rare earth layer is of a composition consisting substantially of [RE1] v [RE2] w [RE3] x [J1] y [J2] z wherein [RE] is chosen from a rare earth; [J1] is oxygen and [J2] is chosen from a group consisting of oxygen (O), nitrogen (N), and phosphorus (P), such that 0≦v, z≦5, and 0≦w, x, y≦5 such that the composition of the rare earth layer adjacent the first semiconductor layer is different from the composition of the rare earth layer adjacent the second semiconductor layer.
9. The device of claim 8 wherein the first and second semiconductor materials are chosen from one or more Group IV elements or alloys.
10. The device of claim 8 wherein the rare earth layer comprises a superlattice of a structure that repeats at least once.
11. The device of claim 8 wherein said rare earth layer comprises; a first region adjacent said first semiconductor layer; a second region adjacent said second semiconductor layer; and a third region separating the first region from the second region such that the composition of the third region is different from the first region and the second region.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
November 16, 2009
November 1, 2011
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